Wireless communication environment in recent years faces a problem of a rapid increase in data traffic. Hence, in 3GPP, installing a large number of small cells in a macro cell to increase network density, thereby distributing traffic, has been under study. Such a technology utilizing small cells is referred to as small cell enhancement. Note that small cells may conceptually include various types of cells (e.g., a femto cell, a nano cell, a pico cell, a micro cell, and the like) that are smaller than a macro cell and are arranged to overlap a macro cell.
In addition, as one way to expand radio resources, utilization of a frequency band of 6 GHz or more, which is called the millimeter-wave band, has been under study. However, since the millimeter-wave band has strong straightness and exhibits large radio propagation attenuation, utilization in a small cell smaller than a macro cell is expected. On the other hand, since the millimeter-wave band is vast, in some cases, even frequency bands included in the same millimeter-wave band may have greatly different radio wave propagation characteristics, as typified by the radio wave propagation attenuation. For this reason, in the vast frequency band of the millimeter-wave band, it is anticipated that a measurement signal for enabling measurement of the downlink quality (hereinafter also referred to simply as the quality) on the terminal apparatus side will be transmitted from a base station. For example, Patent Literature 1 below discloses technology for efficiently executing a process related to a measurement report in accordance with service quality requirements in wireless transmission involving carrier aggregation.